summaryrefslogtreecommitdiff
path: root/testsuite/tests/quasiquotation
diff options
context:
space:
mode:
authorBen Gamari <ben@smart-cactus.org>2015-08-26 18:24:34 +0200
committerBen Gamari <ben@smart-cactus.org>2015-10-29 16:14:51 +0100
commitbef2f03e4d56d88a7e9752a7afd6a0a35616da6c (patch)
tree9ae33978cf43d8268a6c5afa42e7a6c8a7e227a1 /testsuite/tests/quasiquotation
parent40e6214c06bc197dbdfcf9f7345dad1ad271922b (diff)
downloadhaskell-bef2f03e4d56d88a7e9752a7afd6a0a35616da6c.tar.gz
Generate Typeable info at definition sites
This patch implements the idea floated in Trac #9858, namely that we should generate type-representation information at the data type declaration site, rather than when solving a Typeable constraint. However, this turned out quite a bit harder than I expected. I still think it's the right thing to do, and it's done now, but it was quite a struggle. See particularly * Note [Grand plan for Typeable] in TcTypeable (which is a new module) * Note [The overall promotion story] in DataCon (clarifies existing stuff) The most painful bit was that to generate Typeable instances (ie TyConRepName bindings) for every TyCon is tricky for types in ghc-prim etc: * We need to have enough data types around to *define* a TyCon * Many of these types are wired-in Also, to minimise the code generated for each data type, I wanted to generate pure data, not CAFs with unpackCString# stuff floating about. Performance ~~~~~~~~~~~ Three perf/compiler tests start to allocate quite a bit more. This isn't surprising, because they all allocate zillions of data types, with practically no other code, esp. T1969 * T3294: GHC allocates 110% more (filed #11030 to track this) * T1969: GHC allocates 30% more * T4801: GHC allocates 14% more * T5321FD: GHC allocates 13% more * T783: GHC allocates 12% more * T9675: GHC allocates 12% more * T5642: GHC allocates 10% more * T9961: GHC allocates 6% more * T9203: Program allocates 54% less I'm treating this as acceptable. The payoff comes in Typeable-heavy code. Remaining to do ~~~~~~~~~~~~~~~ * I think that "TyCon" and "Module" are over-generic names to use for the runtime type representations used in GHC.Typeable. Better might be "TrTyCon" and "TrModule". But I have not yet done this * Add more info the the "TyCon" e.g. source location where it was defined * Use the new "Module" type to help with Trac Trac #10068 * It would be possible to generate TyConRepName (ie Typeable instances) selectively rather than all the time. We'd need to persist the information in interface files. Lacking a motivating reason I have not done this, but it would not be difficult. Refactoring ~~~~~~~~~~~ As is so often the case, I ended up refactoring more than I intended. In particular * In TyCon, a type *family* (whether type or data) is repesented by a FamilyTyCon * a algebraic data type (including data/newtype instances) is represented by AlgTyCon This wasn't true before; a data family was represented as an AlgTyCon. There are some corresponding changes in IfaceSyn. * Also get rid of the (unhelpfully named) tyConParent. * In TyCon define 'Promoted', isomorphic to Maybe, used when things are optionally promoted; and use it elsewhere in GHC. * Cleanup handling of knownKeyNames * Each TyCon, including promoted TyCons, contains its TyConRepName, if it has one. This is, in effect, the name of its Typeable instance. Requires update of the haddock submodule. Differential Revision: https://phabricator.haskell.org/D757
Diffstat (limited to 'testsuite/tests/quasiquotation')
-rw-r--r--testsuite/tests/quasiquotation/T7918.stdout3
1 files changed, 3 insertions, 0 deletions
diff --git a/testsuite/tests/quasiquotation/T7918.stdout b/testsuite/tests/quasiquotation/T7918.stdout
index f4d406b591..4dff68d1ce 100644
--- a/testsuite/tests/quasiquotation/T7918.stdout
+++ b/testsuite/tests/quasiquotation/T7918.stdout
@@ -25,3 +25,6 @@
(undefined, T7918B.hs:18:16-24)
(y, T7918B.hs:19:9-12)
(undefined, T7918B.hs:19:16-24)
+(Module, <no location info>)
+(TrNameS, <no location info>)
+(TrNameS, <no location info>)